Zusammenfassung der Ressource
Anaemia
- Definition
Anlagen:
- Reduction in haemoglobin concentration
causing decrease in oxygen carrying capacity
- It is not a diagnosis - is an abnormal clinical finding
- RBCs
- 8 um diameter, biconcave, flexible oval
- 10^12 made in bone marrow
everyday - erythropoiesis
- 120 day lifespan - destroyed by
macrophages in spleen
- Haemaglobin
- 640 million molecules per RBC
- Tetrameric structure - 2 pairs of different
polypeptide chains, 1 haem molecule
- Globin (polypeptide chains)
- Permits variability in oxygen affinity
- Protects haem from oxidation
- Makes the molecule soluble
- HbF has higher affinity for oxygen,
HbS has lower affinity (than normal)
- 3 Main types
- HbA - alpha2beta2
- 96-98% in blood
- HbA2 - alpha2delta2
- 1.5-3.2% in blood
- HbF - alpha2gamma2
- 0.5-0.8% in blood
- Contains 65% of body iron
- 30% is ferritin and haemosiderin
- Rest is myoglobin, haem enzymes
(cytochromes), transferrin
- Symptoms
- May not be any - depends on
speed of onset, severity and age
- Tiredness/Lethargy
- Shortness of breath
- Palpitations
- Headaches
- In old people
- Cardiac failure
- Angina
- Intermittent claudication - muscle pain
- Confusion
- Signs
- General
- Pallor of mucous membranes - if Hb <9-10 g/dL
- Hyperdynamic circulation
- Tachycardia
- Bouncing pulse
- Cardiomegaly
- Systolic flow murmur
- Signs of heart failure
- Specific
- Koilonychia (spoon nails) - iron deficiency
- Jaundice - Haemolytic/megaloblastic anaemia
- Leg ulcers - sickle cell disease
- Bone deformities - thalassaemia major
- Associated infetions/bruising - bone marrow failure
- Classification
- Microcytic - MCV <80 fl
- Iron deficiency
- Thalassaemia trait
- Anaemia of chronic disease
- Normocytic - 80-95 fl
- After acute blood loss
- Haemolytic anaemias
- Bone marrow failure
- Macrocytic - >95 fl
- Megaloblastic - vitamin B12/folate deficiency
- Non-megaloblastic - alcohol, liver disease, myelodysplasia
- Investigations
- In all cases
- Full blood count - red cell indices, white cell/platelet count
- Blood film
- Depending on Blood Count/Film
- Reticulocyte count
- Hb electrophoresis
- Bone marrow biopsy
- Taken from pelvis
- Short needle for aspirate
- Long needle for core
- Bilirubin/LDH/haptoglobin test
- Haematinics
- Ferritin, iron studies, vitamin B12, folate
- Microcytic Anaemia
- Most common - 500 million people affected
- Caused by limited ability to absorb iron
- Excess loss due to bleeding common
- Iron requirement goes up in pregnancy,
adolescence and menstruation
- Average daily intake of iron -
10-15 mg (best source is meat)
- Clinical features
- General signs/symptoms
- Painless glossitis (tongue inflammation)
- Angular stomatitis (corners of mouth)
- Koilonychia
- Children
- Irritability
- Poor cognitive function
- Decline in psychomotor development
- Reticuloendothelial stores (haemosiderin and
ferretin) depleted before anaemia develops
- Causes
- Chronic Blood Loss
- Uterine
- Gastrointestinal
- Peptic ulcer disease
- Aspirin/NSAIDs
- Malignancy
- Inflammatory bowel disease
- Hookworm
- Haematuria
- Increased demand
- Prematurity
- Pregnancy
- Growth
- Malabsorption
- Coeliac disease
- Gastrectomy
- Poor diet